一氧化氮抑制牵张刺激心肌细胞肥大反应的实验研究

Inhibitory effect of nitric oxide on hypertrophic response of cardiomyocytes stimulated by stretch in vitro

目的 探讨一氧化氮 (NO)对牵张刺激心肌细胞肥大的抑制作用。方法 用分光光度法、原位杂交及图像分析法测定蛋白、DNA含量及 β MHCmRNA表达。 结果 2 0 %牵张刺激可诱导培养心肌细胞内游离Ca2 + 含量迅速升高 ,12～ 2 4h即见蛋白质合成及 β MHCmRNA显著增加。大于 3× 10 - 4mol L的硝普钠 (NO供体 )可显著抑制牵张刺激诱导的心肌细胞蛋白质合成及 β MHCmRNA表达。NO可同时使牵张刺激引起的细胞内游离Ca2 + 浓度升高受到抑制。结论 一氧化氮可显著抑制牵张刺激诱导的心肌细胞肥大反应 ,这种抑制可能是通过降低细胞内游离Ca2 + 浓度而发挥作用的。

Objective To investigate the inhibitory effect of nitric oxide (NO) on the cardiocyte hypertrophic response stimulated by stretch. Methods Spectrophotometry, in situ hybridilization and image analysis were used to detect changes of protein, DNA contents and β MHC mRNA expression. Results The protein syntheses, β MHC mRNA expression and the concentration of intracellular free Ca 2+ of cardiomyoctes induced by stretch were significantly elevated than that in control. Protein syntheses and β MHC mRNA expression induced by stretch were significantly inhibited by NO (>3×10 -4 mol/L), and the role was persistent if its concentration was kept. Meanwhile, the increase of intracellular free Ca 2+ induced by stretch was also inhibited by NO. Conclusion Cardiocytes hypertrophic response stimulated by stretch could be inhibited by nitric oxide. The inhibitory effect might be due to the decrease of the concentration of intracellular free Ca 2+ .